Splitboarding is an exciting winter sport and is growing internationally. Derived from snowboarding, the splitboarder advantageously can disassemble the splitboard and either can carry the two ski halves or can ski up a slope to a higher elevation; then reassemble the board halves and ride downhill in “descent mode” just as on a one-piece snowboard. Thus the splitboarder is not dependent on ski lifts and can explore virgin backcountry runs with no limitations. Splitboards thus have the flexibility of interconverting between a ski or touring mode and a snowboard descent mode. To achieve the dual function, two boot binding interfaces are provided: a “ski tour interface” is used when skiing, and a “ride mode interface” is used when riding the board in descent mode. Advantageously, the rider's legs are rigidly anchored together on the board in descent mode, reducing the risk of knee injuries common in downhill skiing. Highbacks mounted at the heel roughly even out how sharply a rider can turn on the toeside of the board and provide support for making heelside turns. Without a highback, especially on firm snow, heelside turns are quite difficult.
Splitboards were first made by Ueli Bettenmann, as described European Pat. Doc. Nos. CH681509, CH684825, German Gebrauchsmuster DE9108618, and EP0362782B1, first under the tradename Snowhow, and later in conjunction with Nitro (Seattle, Wash.). Another early entrant commercially was Voile (Salt Lake City, Utah). The popular “Split Decision” introduced a binding system described in U.S. Pat. No. 5,984,324 to Wariakois. The patent describes a “slider track” with insertable toe pivot pin for each foot, the slider track joining pairs of “slider blocks” mounted crosswise on each ski member; the toe pivot pin also serving as a pivot axle for free heel ski touring. This innovation resulted in substantial growth of interest in splitboarding in the United States and has had a worldwide impact on the sport.
Ritter, in U.S. Pat. Nos. 7,823,905, 8,226,109 and in 9,022,412, discloses a stiffer, lower and lighter binding for spanning slider blocks mounted crosswise on the splitboard. These bindings are being commercialized by Spark R&D of Bozeman MT and have developed an international following.
Splitboard binding systems for soft boots typically include an upright member, called a “highback”, that seats behind the heel and supports a rider's calf. The highback improves coupling efficiency, allowing the rider to better control the board through leg movement. For example, leaning back against the highback places the board on its heel edge for a heelside turn, while balancing the rider. Momentum does the rest.
Conventional highbacks generally include an upright support member formed with a pair of lateral pivot ears for mounting the highback to a boot binding apparatus, which includes toe and ankle straps. A splitboard rider's legs are generally held by the highback at a forward angle relative to the board. This stance provides better balance, control and ensures the rider's knees are slightly bent for better shock absorption, particularly in bumpy or variable snow conditions. To hold the rider's leg in such a stance, the highback is typically inclined relative to the board in a position referred to as “forward lean”. A desired amount of forward lean is set by pivoting the highback in the toe direction on the mounting axis and locking its position so that it engages a portion of the boot binding, typically a “heel cup”, to provide leverage against the highback. Increasing the forward lean increases the response of the board on a heelside turn, but at the same time constrains the rider's legs to a degree and can inhibit necessary movements used to negotiate varying terrain. Thus there is a balance to be struck between support and mobility. Each rider is different in what they want, necessitating easy adjustability.
Patent literature related to adjustable highbacks include U.S. Pat. No. 5,713,587 to Morrow, U.S. Pat. No. 6,325,405 to Okajima, U.S. Pat. No. 6,390,492 to Bumgamer, U.S. Pat. No. 7,077,403 to Laughlin and Dodge, and WO 2012/058451 to Morrow. Some of these systems require special keys to operate, and are ratcheted so that adjustment is stepwise instead of smooth. Moreover, these systems are generally specific for snowboards, and lack features as would find use for uphill skiing, simply because uphill skiing is not possible with a snowboard. For uphill touring it is desirable for the highback to recline, allowing the splitboarder maximum stride for efficient travel. The ability to quickly switch between a recline mode and a forward leaning mode is also desirable.
It is an object of the present invention to provide an improved highback suitable for use with a splitboard binding system having both a “ski touring” mode (enabled to perform both downhill and uphill skiing) and a splitboard “ride” mode. There has been a long-standing need for a highback that is more closely adapted for use with splitboards.